In this video, you hear the Corsicans shouting "Arabs out!" at the end.
Tensions had mounted in Ajaccio after two firefighters and a police officer were injured overnight in a low-income neighbourhood of the city when they were "ambushed" by "several hooded youths", authorities said.
On Friday afternoon around 150 people had gathered in front of the prefecture in a show of support for the police and firefighters, officials said in a statement.
But some in that crowd broke away and headed for the low-income housing estate where the violence took place the night before.
They shouted slogans in Corsican meaning "Arabs get out!" or "This is our home!", an AFP correspondent reported. Nearby was the Muslim prayer room and a small group smashed the glass door and entered the place of worship, ransacking the room and partially burning books including copies of the Koran, said regional official Francois Lalanne.
"Fifty prayer books were thrown out on the street," said Mr Lalanne, adding that some of the pages were burnt.Source
The video below shows the enraged Corsicans marching towards the mosque and setting fire to something.